In this blog post, we will explore in depth whether ethical judgment can be explained solely through deduction and whether an absolute standard can exist.
There are many ethical theories. In this article, we will show that ethical theories are meaningless when approached entirely through deduction.
Before we get into the details, let us assume that all ethical theories can be replaced with propositions. One could argue that this assumption is not true, but we will not judge that in this article. Let us pause here for a moment and consider why it is important to assume that ethical theories can be replaced with propositions. This is part of an attempt to understand ethical judgments within a logical system.
Many philosophers and ethicists have used this approach to explain ethical judgments more clearly and consistently. Let us assume that a theory can be expressed as a system of propositions and that the truth or falsity of each proposition can be determined by deductive reasoning. Then, judging a new proposition to be true can be understood as adding a new element to the set of true propositions.
For example, suppose there are three propositions p, q, and r, and proposition s is true when all of them are true. If we already know that p, q, and r are true, we can judge that s is true. This is the same as adding s to the existing set of true propositions {p, q, r} to expand the set of true propositions to {p, q, r, s}. In other words, when judgments about each proposition are made deductively, the act of judging a proposition is equivalent to expanding the set of true propositions. This applies not only when a new proposition is judged to be true, but also when a new proposition is found to be false. This is because judging a proposition to be false is equivalent to adding the negation of that proposition to the set of true propositions.
Ethical theory is no exception. Assuming that ethical theory has a deductive structure, all ethical judgments can be understood as adding elements to the set of true propositions. However, ethical judgments differ from general judgments in that ethical judgments require propositions that contain ethical value judgments. In other words, ethical judgments require not only a set of propositions that are already known to be true, but also propositions that contain ethical value judgments within this set. However, this is where the problem arises. If we trace back the process of deriving propositions that have ethical meaning, we will eventually reach propositions that cannot be derived. In other words, there must be propositions that are ethically true but cannot be justified.
Let’s take a step back and consider whether there really are propositions that cannot be derived. When we continue to reverse inferences from a given proposition, it is only natural that unfounded propositions will appear if the reverse inferences are finite. This is inevitable because reverse inferences will eventually come to an end. But is it impossible for reverse inferences to be infinite? Let’s assume for a moment that infinite reverse inferences are possible. In other words, imagine a chain of propositions with no end, following one after another. Some may feel that the fact that there are countless propositions is a problem, but that is not an issue here. This may seem like a far-fetched example, but suppose there is a true general ethical proposition p. If we consider an infinite number of propositions such as “p is true after one second,” “p is true after two seconds,” “p is true after three seconds,” and so on, all of these propositions are clearly true. Of course, these propositions are true, but they have little practical meaning. However, the key point here is not that these propositions have no practical meaning, but that they contain ethical value judgments and are countless. Therefore, the existence of countless propositions is not a problem.
The problem is reasoning that has no beginning. Reasoning that continues infinitely backward without a starting point cannot determine whether something is true or false. Even if all the links in the chain of reasoning are true, or even if they are all false, there is no problem. In contrast, consider a chain of reasoning that has a starting point but cannot be deduced. Since the opposite of a true proposition is also true, if we assume that the last proposition in this chain is false, that is, that the negation of the last proposition is true, then by tracing back each link in the chain one by one, we eventually arrive at the conclusion that the starting point of the chain, the first proposition, is false. This is a contradiction, so the last proposition in the chain cannot be false. However, this cannot happen in an endless chain with no starting point. Even if we assume that the last proposition in the chain is false, no matter how many links in the chain we trace back, no contradiction will ever appear. In the end, even if all the links in this chain are false, there is no contradiction anywhere. Therefore, this chain could be all true, all false, or, based on some point in the middle, one side could be all true and the other side could be all false. And such a proposition is, at least in ethics, completely useless. If we need to determine right and wrong, what is the point if it could be either right or wrong?
Therefore, we have now reached the conclusion that propositions that cannot be derived must exist in a completely deductive ethical theory. From this, it naturally follows that if there is no standard other than deduction in ethical theory, then any evil deed or crime in this world can be ethically justified.
This is completely contradictory to everyone’s sense of ethics, and therefore, as a corollary to the above proposition, we can be certain that there must be something other than deduction in ethical theory. Of course, that something must also be justified. Looking at the numerous ethical theories of modern and contemporary times, it goes without saying that this something is lacking. Countless people have created propositions that are true in their own eyes and built systems on top of them as they saw fit.
For example, various ethical theories have different cultural and social backgrounds and present their own unique standards and principles. However, these standards sometimes conflict with each other and are often difficult to apply universally. In addition, there is a tendency to focus only on theoretical perfection while overlooking practicality and applicability. It seems that this something is not easy to find. Until the distant future when humans fully understand the brain and, therefore, ethics, we will have no choice but to live with propositions that cannot be justified.
Furthermore, we must also consider that ethical decisions cannot be made solely as a result of logical reasoning. Ethical judgments are made through the complex interaction of human moral intuition, emotions, and experiences. These factors are difficult to explain through deductive reasoning alone. For example, consider a moral dilemma in a specific situation. When judging whether an action is right or wrong, we consider not only logical consistency but also emotional responses, social norms, personal values, and other factors. In order to understand such complex ethical judgment processes, various approaches are necessary in addition to deductive reasoning.
Therefore, ethical theory requires not only a deductive approach but also a multifaceted approach that reflects the complex moral experiences of human beings. This means going beyond the pursuit of logical consistency and attempting to understand how humans actually make moral decisions. Ethical judgments are deeply connected to human nature, and a complete understanding of them requires philosophical, psychological, and sociological insights. Only such an integrated approach will enable a true understanding of ethics.
